Materials Literature
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Abstract Polymandelide was prepared in 77% yield by reaction of α‐bromophenylacetic acid and triethylamine. The product was characterized by 1 H‐ and 13 C‐NMR and IR spectra and isolation and identification of mandelic acid from hydrolysis of the polymer. The NMR spectra indicate the presence of tacticity at CH in the…
TODAY'S modern aeroplanes require light weight components to satisfy the aeroplane's flight performance requirements. More than ever before new designs require commercially pure titanium (Grades A40, A55, and A70) because of the needs for high ductility associated with moderate strength, high corrosion resistance and…
The adsorption of polymeric sulphonated naphthalene formaldehyde (SNF) and sulphonated melamine formaldehyde (SMF) on to titanium dioxide and calcium carbonate has been measured in aqueous media. The magnitude of these adsorptions is strongly dependent on electrostatic interaction irrespective of the pH value. This re…
Long-distance transport of 14C-labelled (photo)assimilates was studied in Fucus serratus. Movement of label followed the source-sink relationship: the growing apical regions of this alga acted as a strong sink. The distribution of the 14C translocate, as determined from the low molecular weight fraction of the midrib,…
Hydrogen permeation and diffusivity were studied electrochemically at temperatures between 283 and 343 K at constant current for annealed and hardened AISI 420 and annealed AISI 430 stainless steel. Permeation rate, effective diffusivity, and solubility were calculated from these data. Annealed AISI 420 shows higher p…
This paper is concerned with the optimization of a double-rove spinning process in the short staple spinning system, using Box and Hunter's technique of a central compound rotatable design. The influences of strand spacing, twist, and spindle speed on yarn tensile and regularity properties are discussed.
Etude par microscopie electronique en transmission de la non stoechiometrie, des phenomenes d'intercroissance et des assemblages des differentes couches dans les mineraux du titre de formule generale M 8 O 12 (M=Mn,Fe,Ca,Si)
An update of the taxa assigned to the genus Mastogloia is given. An estimated 410 taxa have been described as at November 1988. A cross-reference database of the similarities existing between 164 recently described taxa and 83 well-known ones is also reported. This may facilitate the identification of troublesome spec…
Abstract Alkylammonium benzene-, pyridine-3-, p-toluene-, and p-ethylbenzenesulfonates were found to be smectogenic when the cation carries an octyl or longer alkyl group. The thermal stability of the mesophase usually reaches its maximum at the octadecylammonium salt. The temperature range of stable existence is in t…
Steady-state and transient photoconductivity measurements have been made at different temperatures and intensities on the amorphous and partially crystallised films of Se 75 Te 25 prepared by vacuum evaporation. Partial crystallisation is achieved by annealing the films at a particular temperature near the crystallisa…
This paper presents the results of a study that was undertaken to optimize the ratio of the components of a new multicomponent inhibitor blend composed of nitrite/molybdate/inorganic phosphate. The mechanistic aspects of inhibition of the blend were also studied. Weight-loss and polarization data indicated that the op…
XPS and AES was used to detect phosphorus on electropolished copper obtained using different hydroxyethylidenediphosphonic acid (HEDP) concentrations, different p H, and various solutions ( , HEDP, and ). Since no phosphorus was detected on the copper surface, the viscous liquid film that formed could be easily elimin…
A three-band model which consists of one σ→σ* and two major π→π* electronic transitions was developed to account for the birefringence dispersion of a uniaxial liquid crystal. By comparing theory with experimental results, the contribution of each band to the overall birefringence is evaluated. The effect of each band…
Abstract The full structure of a new crystalline form of bis(1,2-diphenyl-1,2-ethenedithiolato)nickel, β-Ni(dpedt)2, has been determined by single crystal X-ray diffraction at room temperature. The structure was refined by full matrix least-squares to a final Rw=0.038. Comparison of this triclinic (P\bar1) structure w…
Abstract The new mineral bernardite has been identified on one specimen from Allchar, Macedonia, Yugoslavia, together with orpiment and realgar. It forms black crystals, the size of which may exceed 1 mm. The streak is deep red; on an arbitrarily oriented section R (589nm) ranges from 23.8 to 24.7% in air, from 10.2 t…
Abstract Short-chain alkylammonium derivatives of montmorillonite (< 8 or 10 C atoms in the alkyl chain) adsorb alcohols in the micropores between the alkylammonium ions. The external surface area and the micropore volume are derived from comparison plots of ethanol and butanol adsorption isotherms. The micropore v…
The type material of the type species of Cyclotella, Cyclotella tecta Håkansson & Ross (syn. C. operculata auct., non (Ag.) Kütz.), has been investigated by light and electron microscopy and compared with the original material of C. distinguenda Hustedt and C. plitvicensis Hustedt, and also with other similar taxa. It…
An alternating electric field is applied to a planarly aligned nematic liquid crystal with a positive dielectric anisotropy sandwiched between two electrodes. This leads to a reorientation of the director when the critical threshold for the Fr\'eedericksz transition is exceeded. Triggered by this reorientation process…
SUMMARY Release of potassium from 15 surface samples of benchmark Alluvial, Red and Black soils of India to 0.01 M solutions of BaCl 2 , CaCl 2 , NH 4 Cl and NaCl was studied in soils either untreated or pretreated with 5 × 10 −3 M KCl. In the untreated soils, the efficacy of the extractants declined in the sequence:…
2,3-Bisphosphoglycerate-independent phosphoglycerate mutase (EC 5.4.2.1) was purified and characterized from maize. SDS electrophoresis showed only one band with a molecular mass of 64 kDa, similar to that determined for the native enzyme by gel-filtration chromatography. The kinetic constants were similar to those re…